Mass antibody testing is being considered by many countries as a way to speed the reopening of economies devastated by lockdowns and to introduce more tailored social distancing measures.

Health minister Matt Hancock said the tests would be first rolled out to staff, patients and residents in health and care settings.

"This is an important milestone, and it represents further progress in our national testing program," he added.

"We're not yet in a position to say that those who test positive in these antibody tests are immune from coronavirus. But as our understanding of the disease improves, the insight these antibody tests provide will be crucial."

The antibody tests - also known as serology tests - show who has been infected, although it is not yet clear whether the presence of antibodies to the new coronavirus, SARS-CoV-2, confers permanent immunity.

Hancock said an antibody surveillance study had found 17% of people in London and around 5% or higher in the rest of the country had tested positive for coronavirus antibodies.

Earlier this month, a spokesman for Prime Minister Boris Johnson said there was the possibility of issuing some kind of certificate based on immunity but that scientists still needed to know more about that subject area.

Hancock also said that Britain would trial a new antigen test - which shows whether people currently have COVID-19, the disease caused by the new coronavirus - that would return results in 20 minutes without needing to be sent to a lab for processing.

"If it works, we'll roll it out as soon as we can," he said.